{"id":100129,"date":"2026-02-15T20:19:19","date_gmt":"2026-02-15T20:19:19","guid":{"rendered":"https:\/\/vibromera.eu\/?post_type=calculator&#038;p=100129"},"modified":"2026-07-12T12:56:57","modified_gmt":"2026-07-12T12:56:57","slug":"heat-loss-wall","status":"publish","type":"calculator","link":"https:\/\/vibromera.eu\/ar\/calculators\/heat-loss-wall\/","title":{"rendered":"\u0622\u0644\u0629 \u062d\u0633\u0627\u0628 \u0645\u0642\u0627\u0648\u0645\u0629 \u0627\u0644\u062c\u062f\u0627\u0631 \u0627\u0644\u0645\u0633\u062a\u0648\u064a\u0629 \u0648\u0627\u0646\u062a\u0642\u0627\u0644 \u0627\u0644\u062d\u0631\u0627\u0631\u0629"},"content":{"rendered":"\r\n<script type=\"application\/ld+json\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"WebApplication\",\"name\":\"Documented Planar-Wall Thermal-Resistance Calculator\",\"description\":\"Calculate layer, total and surface-to-surface thermal resistance, U-value and signed steady heat transfer for a documented homogeneous planar wall 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print{.vc-section-body{max-height:none!important}.vc-faq-a{max-height:none!important}.vc-results{max-height:none!important;padding:24px!important}.vc-copy-btn,.vc-section-chevron,.vc-faq-chevron,.vc-presets,.vc-promo{display:none!important}}.vc-doc-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}.vc-wide{grid-column:1\/-1}.vc-result-note{font-size:13px;color:var(--vc-ink-secondary);margin:0}@media(max-width:600px){.vc-doc-grid{grid-template-columns:1fr}.vc-wide{grid-column:auto}}.vc-doc-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}.vc-wide{grid-column:1\/-1}.vc-layer-list{display:grid;gap:14px;margin-top:12px}.vc-layer-row{border:1px solid var(--vc-border);border-radius:8px;padding:14px;background:var(--vc-surface-alt)}.vc-layer-head{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:10px}.vc-layer-title{font-weight:700}.vc-layer-grid{display:grid;grid-template-columns:2fr 1.4fr 1fr 1fr;gap:12px}.vc-remove-layer{border:1px solid var(--vc-border);background:var(--vc-surface);color:var(--vc-ink);border-radius:6px;padding:7px 10px;cursor:pointer}.vc-add-layer{margin-top:12px;border:1px solid var(--vc-accent);background:var(--vc-accent);color:#fff;border-radius:6px;padding:10px 14px;font-weight:700;cursor:pointer}.vc-formula-box{font-family:var(--vc-mono);background:var(--vc-surface-alt);border:1px solid var(--vc-border-light);border-radius:6px;padding:14px;margin:12px 0;line-height:1.7}.vc-result-note{font-size:13px;color:var(--vc-ink-secondary);margin:0}@media(max-width:700px){.vc-doc-grid,.vc-layer-grid{grid-template-columns:1fr}.vc-wide{grid-column:auto}.vc-layer-head{align-items:flex-start}}<\/style>\r\n<div class=\"vc-calculator\" id=\"vc-wall\"><header class=\"vc-header\"><p class=\"vc-header-eyebrow\">Documented steady one-dimensional case<\/p><h1 class=\"vc-header-title\">Planar-Wall Thermal Resistance &amp; Heat-Transfer Calculator<\/h1><p class=\"vc-header-subtitle\">Sum documented homogeneous layer and surface resistances, calculate U-value, and preserve the sign and direction of the steady heat-transfer rate.<\/p><div class=\"vc-badges\"><span class=\"vc-badge\">R = d\/\u03bb<\/span><span class=\"vc-badge\">U = 1\/Rtotal<\/span><span class=\"vc-badge\">Signed Q = UA(Ti\u2212Te)<\/span><\/div><\/header>\r\n<div class=\"vc-card\"><form class=\"vc-form\" id=\"vc-form\" autocomplete=\"off\"><div class=\"vc-doc-grid\"><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-id\">Assembly \/ project identifier<\/label><input class=\"vc-input\" id=\"vc-id\" type=\"text\" maxlength=\"220\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-case\">Boundary-temperature case, source and revision<\/label><input class=\"vc-input\" id=\"vc-case\" type=\"text\" maxlength=\"450\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-ti\">Inside-side temperature Ti <span class=\"vc-label-hint\">(\u00b0C)<\/span><\/label><input class=\"vc-input\" id=\"vc-ti\" type=\"text\" inputmode=\"decimal\" maxlength=\"80\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-te\">Outside-side temperature Te <span class=\"vc-label-hint\">(\u00b0C)<\/span><\/label><input class=\"vc-input\" id=\"vc-te\" type=\"text\" inputmode=\"decimal\" maxlength=\"80\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-area\">Documented net heat-flow area A <span class=\"vc-label-hint\">(m\u00b2)<\/span><\/label><input class=\"vc-input\" id=\"vc-area\" type=\"text\" inputmode=\"decimal\" maxlength=\"80\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-area-source\">Area take-off \/ geometry source<\/label><input class=\"vc-input\" id=\"vc-area-source\" type=\"text\" maxlength=\"400\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-rsi\">Inside surface resistance Rsi <span class=\"vc-label-hint\">(m\u00b2\u00b7K\/W)<\/span><\/label><input class=\"vc-input\" id=\"vc-rsi\" type=\"text\" inputmode=\"decimal\" maxlength=\"80\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-rsi-source\">Rsi boundary-condition source<\/label><input class=\"vc-input\" id=\"vc-rsi-source\" type=\"text\" maxlength=\"400\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-rse\">Outside surface resistance Rse <span class=\"vc-label-hint\">(m\u00b2\u00b7K\/W)<\/span><\/label><input class=\"vc-input\" id=\"vc-rse\" type=\"text\" inputmode=\"decimal\" maxlength=\"80\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-rse-source\">Rse boundary-condition source<\/label><input class=\"vc-input\" id=\"vc-rse-source\" type=\"text\" maxlength=\"400\"><\/div><\/div>\r\n<div class=\"vc-field vc-wide\" style=\"margin-top:18px\"><span class=\"vc-label\">Solid homogeneous layers, entered from either side<\/span><div class=\"vc-help-text\">For each solid layer, cite the product\/design conductivity source and revision. Air or gas layers and cavities require a different resistance method and are not accepted by this d\/\u03bb ledger.<\/div><div class=\"vc-layer-list\" id=\"vc-layers\"><\/div><button type=\"button\" class=\"vc-add-layer\" id=\"vc-add-layer\">+ Add documented solid layer<\/button><\/div><p id=\"vc-error\" role=\"alert\" style=\"margin:.75rem 0 0;color:#b42318\"><\/p><div class=\"vc-warning-box\"><p style=\"margin:0\"><strong>Applicability gate:<\/strong> this calculator supports only a plane component represented as solid homogeneous material layers in series under a documented steady one-dimensional boundary case. It does not model air\/gas layers or cavities, thermal bridges, studs\/fasteners, air leakage, ground coupling, windows\/doors, moisture, solar gain or transient thermal storage.<\/p><\/div><\/form>\r\n<div class=\"vc-results\" id=\"vc-results\" aria-live=\"polite\"><div class=\"vc-results-head\"><h2 class=\"vc-results-title\">Documented planar-wall result<\/h2><button type=\"button\" class=\"vc-copy-btn\" id=\"vc-copy-btn\">Copy<\/button><\/div><div class=\"vc-result-grid\"><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Layer resistance sum \u03a3(d\/\u03bb)<\/div><div class=\"vc-rcard-value\" id=\"vc-r-layers\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Total resistance Rtotal<\/div><div class=\"vc-rcard-value\" id=\"vc-r-total\">\u2014<\/div><\/div><div class=\"vc-rcard vc-rcard-primary\"><div class=\"vc-rcard-label\">Thermal transmittance U<\/div><div class=\"vc-rcard-value\" id=\"vc-r-u\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Signed temperature difference Ti\u2212Te<\/div><div class=\"vc-rcard-value\" id=\"vc-r-dt\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Signed heat flux q<\/div><div class=\"vc-rcard-value\" id=\"vc-r-flux\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Signed heat-transfer rate Q<\/div><div class=\"vc-rcard-value\" id=\"vc-r-q\">\u2014<\/div><\/div><\/div><p class=\"vc-result-note\" id=\"vc-r-note\"><\/p><\/div><\/div>\r\n<div class=\"vc-section vc-open\"><button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"true\"><span class=\"vc-section-toggle-text\"><span class=\"vc-section-icon\">\ud83d\udcd8<\/span><span class=\"vc-section-title\">Equations, source and design boundary<\/span><\/span><\/button><div class=\"vc-section-body\"><div class=\"vc-section-inner vc-theory\"><h3>Implemented arithmetic<\/h3><div class=\"vc-formula-box\">Ri = di\/\u03bbi<br>Rlayers = \u03a3Ri<br>Rtotal = Rsi + Rlayers + Rse<br>U = 1\/Rtotal<br>q = U(Ti\u2212Te)<br>Q = A\u00b7q<\/div><p>Thickness <em>d<\/em> is converted from millimetres to metres. Conductivity \u03bb is entered in W\/(m\u00b7K), resistance in m\u00b2\u00b7K\/W, U in W\/(m\u00b2\u00b7K), heat flux in W\/m\u00b2 and total rate in W. Positive Q means transfer from the entered inside side toward the entered outside side; negative Q means the reverse direction.<\/p><h3>Standard status and scope<\/h3><p><a href=\"https:\/\/www.iso.org\/standard\/65708.html\" target=\"_blank\" rel=\"noopener\">ISO 6946:2017<\/a>, edition 3, is Published and was confirmed in 2022; ISO lists a corrected English version dated 2021-12. Its scope covers calculation of resistance and transmittance for building components using appropriate design conductivities or resistances and thermally homogeneous layers. The ISO page excludes doors\/windows\/glazing, curtain walling, ground heat transfer and components designed for air permeation, and states that bridged\/inhomogeneous cases require additional treatment.<\/p><p>This page performs only the displayed series-resistance arithmetic. It does not claim an ISO 6946 compliance calculation because it does not implement the complete licensed procedure, air-layer rules, inhomogeneous-layer method or Annex F corrections. No ISO clause or table is asserted without checking the licensed text.<\/p><h3>Why fixed defaults and presets were removed<\/h3><p>The former calculator silently imposed Rsi=0.13 and Rse=0.04 m\u00b2\u00b7K\/W, supplied unsourced conductivity presets and generic \u201ctypical U-value\u201d ranges, and used |Ti\u2212Te| so an outside-to-inside heat gain was still labelled heat loss. Surface resistance and design conductivity depend on the documented boundary and product\/application case; this version therefore requires their sources and preserves the sign. An <a href=\"https:\/\/www.ofgem.gov.uk\/sites\/default\/files\/docs\/2017\/05\/uv_summary_report.pdf\" target=\"_blank\" rel=\"noopener\">Energy Saving Trust report published by Ofgem<\/a> documents missing \u03bb-source evidence and a real calculator error caused by treating air layers with a fixed conductivity; this ledger therefore accepts only an explicitly selected solid homogeneous d\/\u03bb model.<\/p><div class=\"vc-warning-box\"><p style=\"margin:0\"><strong>Not an energy-code or condensation assessment:<\/strong> verify national annexes and code methods, design conductivity\/resistance, geometry, surface orientation and environment, repeating\/non-repeating bridges, openings, junctions, ventilation\/infiltration, moisture\/condensation, solar and long-wave radiation, transient conditions and uncertainty.<\/p><\/div><\/div><\/div><\/div><footer class=\"vc-footer\"><p>\u00a9 2024\u20132026 <a href=\"https:\/\/vibromera.eu\/\">Vibromera<\/a><\/p><p>Documented solid homogeneous-layer arithmetic only. 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